Incandescent lamp



1938- D. P. GALLAGHER I 2,104,555

INCANDESGENT LAMP Filed Jan. 5, 1936 IN ENTOR ATTORNEY Patented Jan. 4, 1938 UITE fiTTES PATENT OFFlCE 2 Claims.

This invention relates to incandescent lamps.

It is an object of this invention to provide a new and improved incandescent lamp which will have a superior distribution of illumination and 5 which, at the same time, will be simple and economical to construct.

In lighting by incandescent lamps, it is customary to place the filament in the form of an arc of a circle and this produces a concentration of illumination along the axis through the center of the arc.

It is a further object of this invention to provide a new and novel shaped bulb which will effect a maximum of diffusion of the light rays along the axis but which will provide a direct egress for light waves passing at an angle to the axis to equalize the illumination throughout a more extended area.

The invention accordingly comprises the features of construction, combination of elements,

and arrangement of parts, which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawing, in which:

Figure l is a top plan view of a lamp made in accordance with this invention.

Figure 2 is a side elevation of the same.

In the drawing the numeral it comprises a base attached to an envelope or bulb portion ll, within which is mounted a filament l2 upon a stem is being fed from lead-in wire i lli connected to the base ii] in the usual manner. The envelope I l comprises a body portion 85 having a cylindrical extension l6, having a curved end wall i'i. This cylinder portion Hi has its lower end [8 situated materially above the plane of the filament H2. The body portion 55 of the end cap I7 is frosted in any desired manner but the cylinder portion l6 preferably remains clear. By the word frosted or translucent is meant any form of treatment which will permit light to pass through with as little obstruction as possible but with diffusion in contrast to clear glass.

With this construction it would be evident that light passing laterally outward from the filament I2 will strike the frosted side walls of the body portion !5 and be diffused there and light passing upwardly along the axis of the lamp will be diffused by the frosted end wall ll, but light passing out at an angle will pass through the clear walls of the cylinder walls l'i.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a. limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. An incandescent lamp comprising a bulb having a contracted top portion and an extension closing said contracted top, said extension being of smaller diameter than the bulb, said extension having a cylindrical side wall and an end wall, the walls of said bulb and said contracted portion thereof being translucent, and the side wall of said extension being clear, a filament within said bulb portion.

2. An incandescent lamp comprising a bulb having a contracted top portion and an extension closing said contracted top, said extension being of smaller diameter than the bulb, said extension having cylindrical side wall and an end wall, the walls of said bulb and said contracted portion thereof being translucent, and the side wall of said extension being clear, the diameter of the translucent portion on the end Wall of said extension being substantially equal to the diameter of the upper end of the contracted portion of the bulb, and a filament within said bulb portion.

.DANIEL P. GALLAGHER.

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